This invention relates generally to capacitors.
Integrated capacitors may be formed of a variety of materials. In some cases, relatively high capacitance density may be desirable. Capacitance density is generally measured as capacitance per unit area. A high capacitance density is generally one microFarad per square centimeter.
One such application is for capacitors for decoupling a power supply for integrated circuits. Such capacitors may use multilayered ceramic, aluminum polymer, and tantalum materials. Generally, aluminum and tantalum capacitors have a higher capacitance density than other capacitors. In addition, aluminum and tantalum capacitors have linear dielectric layers so there is not the large variation with electric field and temperature that ceramic capacitors may exhibit.
The greater the capacitance density, the more effective the capacitor may be for the same amount of area consumed. Thus, a higher capacitance density may result in a more densely packed semiconductor structure.